Elevator fan faulty
- Causes
- Inoperative elevator fan is mainly due to the emergency supply power fail to operate during power failure of the system
- Excessive vibration – Vibration is caused by loose impeller due to loose connection where nut is not secure in its place. Vibration also can be caused due to cracks and distortion and unbalance of the impeller plate
- Inadequate airflow output from blower – Oily fumes and dust in the atmosphere may deposit and accumulate in the form of caked substance which can be grow on the wire mesh of the air passage and on the surface of the impeller
- Description of defect
Failures of fans are relatively rare as the components only consist a cast or welded impellers inside the steel casings. Failures normally occur due to wear and deficiency during manufacturing process.
A condition of dirty fan located on top of elevator car [27]
- Diagnostic/testing method
Basic maintenance for includes periodic inspection and fan cleaning. The contaminants build up on the surfaces need to be removed as it can disturb the air-flow resulting in decreased fan efficiency and higher operating cost
- Good practices
Lift car shall be provided with ventilation fan installed in the upper and lower parts if the cars, where exhaust type are recommended to extract stale air from inside of the lift car. The air change rate shall be 20 times per hour. For air conditioned lift cars, the air conditioning fan or separate fan shall be powered by EBOPS during power failures (SS550).
- Corrections
The type of fan used will determine the its performance I terms of the noise production, amount of input air, pressure of the wind-blown, and its service life.
Example of elevator cross flow fan [28]